This disclosure relates generally to online systems, and more specifically to selecting content for presentation to a user of an online system based on categories associated with content items.
An online system allows its users to connect and communicate with other online system users. Users create profiles maintained by the online system that are tied to their identities and include information about the users, such as interests and demographic information. The users may be individuals or entities such as corporations or charities. Because of the popularity of online systems and the significant amount of user-specific information maintained by online systems, an online system provides an ideal forum for allowing users to share content by creating content items for presentation to additional online system users. For example, users may share photos or videos they have uploaded by creating content items that include the photos or videos. These content items are then presented to additional users to which the users are connected in the online system. By presenting content items to its users, an online system creates additional opportunities for the users to share their reactions to the content items. For example, users may express a preference for, comment on, or share content items with additional users of the online system.
An online system also provides advertisers with abundant opportunities to increase awareness about their products or services by presenting advertisements to online system users.
For example, advertisements presented to users allow an advertiser to gain public attention for products or services and to persuade online system users to take an action regarding the advertiser's products, services, opinions, or causes. Advertisements presented to online system users also may enable the users to easily make purchases or subscribe to services provided by advertisers. For example, an advertisement presented to users on the online system may be linked to a landing page, such that users who click on the advertisement are redirected to the landing page, where they may purchase products or services associated with the advertisement.
Conventionally, online systems generate revenue by displaying content items, such as advertisements, to their users. For example, an online system may charge advertisers for each presentation of an advertisement to an online system user (i.e., each “impression”), or for each interaction with an advertisement by an online system user. Furthermore, by presenting content items that users are likely to find interesting, online systems may increase the number of opportunities they have to generate revenue. For example, if a user scrolls through a newsfeed to view content items that capture their interest, advertisements that are interspersed in the newsfeed may be presented to the user. Online systems may also increase the number of opportunities they have to generate revenue by presenting content items that encourage user engagement with the online systems. For example, if a user finds a content item interesting, they are more likely to comment on, express a preference for, or share the content item, which in turn, creates more content items with which additional users may find interesting and/or interact. Therefore, online systems may maximize their revenue by presenting content items in which users are likely to have an interest and with which they are likely to interact.
However, users may be more likely to interact with content items during particular times than others. For example, a user who has a busy job may be more likely to comment on or share content items with other users to whom they are connected in the online system on weekends than on weekdays. Similarly, users who recently performed an action in association with being presented with a content item may be less likely to perform a similar action anytime soon. For example, if a user donates $500 to a charity after clicking through an advertisement for the charity, the user is unlikely to make another donation to the same or a similar charity a few days or even a few weeks later. In these and other circumstances, online systems may have difficultly identifying content items with which users are likely to interact. Thus, online systems may waste opportunities to present content items with which their users are likely to interact, which may be detrimental to the online systems and their users.